#pragma once


#include<iostream>

using namespace std;

namespace key
{
	template<class K>
	struct BSTNode
	{
		K _key;
		BSTNode<K>* _left;
		BSTNode<K>* _right;

		BSTNode(const K& key)
			:_key(key)
			, _left(nullptr)
			, _right(nullptr)
		{ }
	};

	template<class K>
	class BSTree
	{
		typedef BSTNode<K> Node;
	public:
		bool insert(const K& key)
		{
			if (_root == nullptr)
			{
				_root = new Node(key);
				return true;
			}
			Node* pcur = _root;
			Node* parent = nullptr;
			while (pcur)
			{
				if (key > pcur->_key)
				{
					parent = pcur;
					pcur = pcur->_right;
				}
				else if (key < pcur->_key)
				{
					parent = pcur;
					pcur = pcur->_left;
				}
				else
				{
					return false;
				}
			}
			pcur = new Node(key);
			if (key > parent->_key)
			{
				parent->_right = pcur;
			}
			else
			{
				parent->_left = pcur;
			}
			return true;
		}

		bool Find(const K& key)
		{
			Node* pcur = _root;
			Node* parent = nullptr;
			while (pcur)
			{
				if (key > pcur->_key)
				{
					parent = pcur;
					pcur = pcur->_right;
				}
				else if (key < pcur->_key)
				{
					parent = pcur;
					pcur = pcur->_left;
				}
				else
				{
					return true;
				}
			}
			return false;
		}

		bool Erase(const K& key)
		{
			Node* pcur = _root;
			Node* parent = nullptr;
			while (pcur)
			{
				if (key > pcur->_key)
				{
					parent = pcur;
					pcur = pcur->_right;
				}
				else if (key < pcur->_key)
				{
					parent = pcur;
					pcur = pcur->_left;
				}
				else
				{
					if (pcur->_left == nullptr)
					{
						if (pcur == _root)
						{
							_root = pcur->_right;
						}
						else
						{
							if (pcur == parent->_left)
							{
								parent->_left = pcur->_right;
							}
							else
							{
								parent->_right = pcur->_right;
							}
						}
						delete pcur;
					}
					else if (pcur->_right == nullptr)
					{
						if (pcur == _root)
						{
							_root = pcur->_left;
						}
						else
						{
							if (pcur == parent->_left)
							{
								parent->_left = pcur->_left;
							}
							else
							{
								parent->_right = pcur->_left;
							}
						}
						delete pcur;
					}
					else
					{
						Node* replace = pcur->_left;
						Node* ReplaceParent = pcur;
						while (replace->_left)
						{
							ReplaceParent = replace;
							replace = replace->_left;
						}
						swap(pcur->_key, replace->_key);
						if (ReplaceParent->_left == replace)
						{
							ReplaceParent->_left = replace->_right;
						}
						else
						{
							ReplaceParent->_right = replace->_right;
						}
						delete replace;
					}
					return true;
				}
			}
			return false;
		}

		void _InOrder(Node* root)
		{
			if (root == nullptr)
			{
				return;
			}
			_InOrder(root->_left);
			cout << root->_key << ' ';
			_InOrder(root->_right);
		}

		void InOrder()
		{
			_InOrder(_root);
			cout << endl;
		}

	private:
		Node* _root = nullptr;
	};
}

namespace key_value
{
	template<class K, class V>
	struct BSTNode
	{
		K _key;
		V _value;
		BSTNode<K, V>* _left;
		BSTNode<K, V>* _right;

		BSTNode(const K& key, const V& value)
			:_key(key)
			,_value(value)
			, _left(nullptr)
			, _right(nullptr)
		{ }
	};

	template<class K, class V>
	class BSTree
	{
		typedef BSTNode<K, V> Node;
	public:
		bool insert(const K& key, const V& value)
		{
			if (_root == nullptr)
			{
				_root = new Node(key, value);
				return true;
			}
			Node* pcur = _root;
			Node* parent = nullptr;
			while (pcur)
			{
				if (key > pcur->_key)
				{
					parent = pcur;
					pcur = pcur->_right;
				}
				else if (key < pcur->_key)
				{
					parent = pcur;
					pcur = pcur->_left;
				}
				else
				{
					return false;
				}
			}
			pcur = new Node(key, value);
			if (key > parent->_key)
			{
				parent->_right = pcur;
			}
			else
			{
				parent->_left = pcur;
			}
			return true;
		}

		Node* Find(const K& key)
		{
			Node* pcur = _root;
			Node* parent = nullptr;
			while (pcur)
			{
				if (key > pcur->_key)
				{
					parent = pcur;
					pcur = pcur->_right;
				}
				else if (key < pcur->_key)
				{
					parent = pcur;
					pcur = pcur->_left;
				}
				else
				{
					return pcur;
				}
			}
			return nullptr;
		}

		bool Erase(const K& key)
		{
			Node* pcur = _root;
			Node* parent = nullptr;
			while (pcur)
			{
				if (key > pcur->_key)
				{
					parent = pcur;
					pcur = pcur->_right;
				}
				else if (key < pcur->_key)
				{
					parent = pcur;
					pcur = pcur->_left;
				}
				else
				{
					if (pcur->_left == nullptr)
					{
						if (pcur == _root)
						{
							_root = pcur->_right;
						}
						else
						{
							if (pcur == parent->_left)
							{
								parent->_left = pcur->_right;
							}
							else
							{
								parent->_right = pcur->_right;
							}
						}
						delete pcur;
					}
					else if (pcur->_right == nullptr)
					{
						if (pcur == _root)
						{
							_root = pcur->_left;
						}
						else
						{
							if (pcur == parent->_left)
							{
								parent->_left = pcur->_left;
							}
							else
							{
								parent->_right = pcur->_left;
							}
						}
						delete pcur;
					}
					else
					{
						Node* replace = pcur->_left;
						Node* ReplaceParent = pcur;
						while (replace->_left)
						{
							ReplaceParent = replace;
							replace = replace->_left;
						}
						swap(pcur->_key, replace->_key);
						swap(pcur->_value, replace->_value);
						if (ReplaceParent->_left == replace)
						{
							ReplaceParent->_left = replace->_right;
						}
						else
						{
							ReplaceParent->_right = replace->_right;
						}
						delete replace;
					}
					return true;
				}
			}
			return false;
		}

		void _InOrder(Node* root)
		{
			if (root == nullptr)
			{
				return;
			}
			_InOrder(root->_left);
			cout << root->_key << ' ';
			_InOrder(root->_right);
		}

		void InOrder()
		{
			_InOrder(_root);
			cout << endl;
		}

	private:
		Node* _root = nullptr;
	};
}